Published 4:00 am, Saturday, May 13, 2006

Google Inc. is making its first foray into mobile telephone calls in a partnership with Nokia Corp., the largest maker of handheld mobile devices.

The deal is expected to be unveiled Tuesday at an event in Sweden, according to a person familiar with the plans.

The agreement calls for Nokia to introduce a handheld device that comes loaded with the Mountain View company's Google Talk, an instant messenger and Internet calling service.

Cellular signals will not be used for the calls. Instead, the calls will be made using a wireless Internet network, known as Wi-Fi. Such access is available in many homes and cafes that have Wi-Fi hot spots. Wi-Fi is also increasingly available through civic projects that blanket entire cities with wireless Internet connections.

Mobile Wi-Fi calling is a growing area of interest for many technology companies that see it as an alternative to cellular service. Vonage, a major Internet calling company, already offers a mobile phone for Wi-Fi, while Skype, owned by San Jose's eBay, plans to introduce a similar phone this year.

The primary attraction of Internet telephone calls, known as voice over Internet protocol, is cheaper prices than cellular service. However, sound quality is sometimes a problem, although the technology has vastly improved over the years on personal computers.

Google's interest in mobile calling comes as it and its partner, EarthLink, negotiate a high-profile contract with San Francisco to cover the city with a Wi-Fi network. Service is expected to be available by the end of the year.

Google's partnership with Nokia relates to an upgraded version of the Nokia 770 Internet Tablet, a handheld device that is slightly larger than a personal organizer. The Nokia device features a wide high-resolution screen and costs around $360.

Users of Google's calling feature will be able to talk directly into the Nokia tablet or use a headset. Calls will be limited to individuals who also have Google Talk software on their Nokia devices or personal computers.

Mobile Wi-Fi, which has recently been introduced, is still a fringe product. Moreover, the calls made on such devices come with a big inconvenience -- Wi-Fi-enabled mobile devices work only in the limited areas where Wi-Fi access is available.

Companies are trying to overcome this hurdle by developing mobile devices that can switch between Wi-Fi and cellular networks.

Like many Internet companies, Google is aggressively pushing its services onto mobile devices, which are increasingly being used by consumers to access the Internet. The search-engine giant has previously signed deals with mobile-phone companies including Motorola Inc., to include the Google search icon; Sony Ericsson, to make Google blogging software available; and Siemens AG, to offer Google's maps.